I'd never took long flights, however curios if one day I'll fly to NewYork from India and I wish to eat my favourite dish, which may not available in kitchen of my flight, what they will do? Is there something that I've to choose from the menu only? If so, I ordered one from the menu and its not available there? However I will force air hostess to get that particular dish for me, what can be done in this situation?
There is only so much food on the plane while it's in the air. If the dish is not available then it is not available.
Should you then throw a tantrum and the flight-attendant judges that you are a danger to themselves or other passengers or the continued flight; the pilot will then divert the flight and throw you off at the nearest available airport. After that you may be fined for the trouble you gave them.